Primary explosives are used in small quantities to generate a detonation wave when subjected to a flame, heat, impact, electric spark, or friction. Detonation of the primary explosive initiates the secondary booster, main-charge explosive, or propellant.
Toxic mercury fulminate, lead azide, and lead styphnate are three common primary explosives, but their deleterious environmental impacts and effects on human health have made their replacement essential. Countless numbers of energetic compounds have been designed and screened as possible primaries, including organic compounds, organic salts, zwitterions, simple organic salts, coordination complexes, and metastable interstitial composites, but none have simultaneously met the six criteria for green primaries: (i) insensitive to moisture and light; (ii) sensitive to initiation but not too sensitive to handle and transport; (iii) thermally stable to at least 200° C.; (iv) chemically stable for extended periods; (v) devoid of toxic metals such as lead, mercury, silver, barium, or antimony; and (vi) free of perchlorate. Thus, a need remains for environmentally friendly, or green, primary explosives.